no sound from subwoofer ( avia Home Theater dvd)

[mathprav]

i have done following test on my home theatre system using the AVIA Home Theater Testing DVD,
the bass mode is set to all small speakers, have a passive subwoofer,
when i have done the channel identification test, i hear the lfe sound from the front left speaker, but don't hear anything from the subwoofer??

also when i do other subwoofer tests, can hear the sound from the main speakers but not from the subwoofer?
am i doing the correct tests? is the results are expected ones, or else my dvd receiver is not working ?

please help me, as i still have warranty and can ask for the fix if it's the problem with the receiver.

thank you for the help....

 

[markw]

A passive subwoofer?

I don't know how you have this hooked up, but the disc is sending a signal to the ".1" channel, which goes out of the LFE jack on your receiver to a powered subwoofer.

If it's not hooked up there, it won't send a signal to your subwoofer. And, you're not getting the LFE channel, either.

 

[mathprav]

have hooked up the subwoofer jack properly and the subwoofer is working fine, have played a dvd movie, and can hear some sound coming out from the subwoofer ( but volume is low),
100% sure that i have hooked up properly.

when i turned the volume on the receiver to max, then actually during the test, i can hear very low sound coming out of the subwoofer, but compared to main speakers the sound is almost nothing!!

is this the expected result of the testing!

 

[markw]

No, that is NOT the expected result.

Why do you say it's a "passive" subwoofer?

Is it hooked up as I described? If not, exactly how is it hooked up?

And, if the subwoofer were working, as you say, "fine", well then, we wouldn't be having this discussion, now would we?

 

[MDS]

i have done following test on my home theatre system using the AVIA Home Theater Testing DVD,
the bass mode is set to all small speakers, have a passive subwoofer,
when i have done the channel identification test, i hear the lfe sound from the front left speaker, but don't hear anything from the subwoofer??

If the subwoofer is indeed passive then it has no internal amplifier. The sub pre-out on the receiver is sending a line-level signal which must be amplified. You can hear it slightly because it is just high enough (about 1 volt) to minimally move the woofer.

You need a powered subwoofer to use the sub pre-out on the receiver. A passive sub needs to get a high level (already amplified) signal. You can connect the front left and right speaker terminals of the receiver to the sub and then the sub to the front speakers. If you do that you must also set the front speakers to Large and subwoofer=No in the receiver setup.

 

[markw]

If the subwoofer is indeed passive then it has no internal amplifier. The sub pre-out on the receiver is sending a line-level signal which must be amplified. You can hear it slightly because it is just high enough (about 1 volt) to minimally move the woofer.

You need a powered subwoofer to use the sub pre-out on the receiver. A passive sub needs to get a high level (already amplified) signal. You can connect the front left and right speaker terminals of the receiver to the sub and then the sub to the front speakers. If you do that you must also set the front speakers to Large and subwoofer=No in the receiver setup.

Good point but heshould beaware that in this scenario there will be no distinct output to the "subwoofer channel". It'll bleed thru to the R/L aswell as the subwoofer.

 

[mathprav]

thanks MDS for your clarification,
let me put in more details,
I have bought this dvd home theatre system ( have in built amplifier according to the specifications) and all the 6 six ( 2 front, 2 rear, center and a subwoofer) speakers have come with the dvd system,
so if the built in amplifier is not sending the amplified signal to the subwoofer, then in the first place i need to argue with them why they have provided the passive subwoofer if the signal is not amplified!

am i right MDS? if i am right then will contact the manufacturer for explanation...

once again thank you MDS and MARK

 

[MDS]

Which DVD home theater system did you purchase? If you provide the make and model number one of us could look at the manual or a picture of the system and determine if the sub is passive or not. A link to the system and/or manual would make it easy to determine.

 

[mathprav]

Hi MDS,
The dvd player which i have bought is local made( singapore)
here's the url

http://www.myakira.com/global/ProductDetail/default.asp?ProductId=449&CatId=,2,24

but they don't have any online manual !!!

accoding to what u said, it looks to me that either the built in amplifier has some problem! if the built in amplifier is not supposed to amplify the subwoofer output , then what's the use of providing the passive subwoofer?

MDS, can u suggest me anyother test to confirm this?

 

[MDS]

I'll take a look at the URL and see if it provides any useful information. The subwoofer pre-out on the receiver is not supposed to amplify the signal (hence the term 'pre-out' - after the preamplifier but before the amplifier).

 

[MDS]

Well that URL doesn't really answer any questions for me. Any chance you could take a picture of the back of the receiver and subwoofer?

If the subwoofer IS amplified then your problem may simply be that you have the sub volume control set too low. If it is not a powered subwoofer then your only option would be to connect it to the receiver's speaker terminals but that requires that the sub also have speaker level outputs. Did the system come with any kind of manual describing hookup options?

 

[mathprav]

system manual doesnt have any hookup options,
at the back of the receiver, there are speaker output(+ -) for SW,CE, FL,FR,SL and SR, that's all

subwoofer is not powered( hence no volume control) ( it has only 2 inputs to be connected that's + and - )

the connecting wires doesnt' have any jack ( banana or others), it's just the two wire(+ and -) that get connected.

that's all mds...
any help?

 

[markw]

Actually, it sort of does, by omission. You gets no bread with one meat ball.**

Well that URL doesn't really answer any questions for me. Any chance you could take a picture of the back of the receiver and subwoofer?

You're right, it doesn't say much but please note two bullet points in particular.

http://www.myakira.com/global/ProductDetail/default.asp?ProductId=449&CatId=,2,24

The first one says "5,1", but is that DD, DTS or what? Methinks none of the above. Why?

Please note thet bullet point four clarifies this somewhat by specying "dolby pro logic"? Odds are this only a Dolby Pro Logic system, which has no discrete subwoofer/LFE channel. It most likely derives the "subwoofer" signal from the front R/L signal and its power from the front R/L channel power amps. IOW, that ain't the LFE track and it ain't a "real" subwoofer.

After looking at the other offerings by this company, I do note that only the "top of the line" from this manufacturer mentions anything except DPL.

http://www.myakira.com/global/ProductDetail/default.asp?ProductId=450&CatId=,2,24

It specifies Dolby AC-3, which is TRUE 5.1, and I would expect (but who knows?) a discrete LFE signal from that one.

And, as for that "5.1" and truth in advertising? Remember, we're not dealing with a product that is sold here in the USA under that name. He might want to take that up with his local better business bureau.

** http://thegurglingcod.typepad.com/thegurglingcod/2006/06/you_gets_no_bre.html

 

[mathprav]

well mark, in the manuals and on the receiver specified that it supports dolby digital ac3 and it has dolby digital ac3 decoder 5.1 channel output!
hope with this specification in the manuals, i can argue with them that the receiver is not working as expected, otherwise why they have given settings for small speakers, large speakers and mentioned that it's for bass manangement and controls the subwoofer volume!

 

[markw]

Well mac, the web site you pointed us to disputes that. One would think they woould promote AC-3 rather than DPL, like they do on the 98, their "TOTL" system.

Then again, you may want to take this matter up with their customer support.

 

[mathprav]

thank you for the help mark, since i am a newbie gathering information from experts so that when i visit the service center , can make them understand and talk about the expected test results....

 

[mathprav]

hi markw and mds,
I have done the same testing at my friends place who has bought the same brand, but lower end model( same feature set) than mine, and to my shock found out that his system is excellent and the sound quality was far superior than mine!!! once again want to repeat that the features are exactly same , can conclude from this that my home theatre system's bass management and internal amplifier is not working as expected.....